This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A257629 #42 Aug 23 2019 02:42:17
%S A257629 1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,1,1,0,0,1,0,1,0,1,1,1,1,0,0,
%T A257629 1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,
%U A257629 2,2,1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,2,2,1,1,2,1,2,1,2,2,3
%N A257629 Duplicate of A276729.
%F A257629 a(n) = A055642(n) - A193238(n). - _Michel Marcus_, Jul 14 2015
%e A257629 a(10344) = 4 because 4 of the digits of 10344 (1, 0, 4 and 4) are nonprime.
%t A257629 a[n_] := Length@ Intersection[ IntegerDigits[n], {0, 1, 4, 6, 8, 9}]; a/@ Range[0, 90] (* _Giovanni Resta_, Jul 14 2015 *)
%t A257629 Table[Count[IntegerDigits[n],_?(!PrimeQ[#]&)],{n,0,100}] (* _Harvey P. Dale_, Jan 16 2017 *)
%Y A257629 Cf. A055642 (number of digits), A193238 (number of prime digits), A046034.
%K A257629 dead
%O A257629 0,11
%A A257629 _Giovanni Teofilatto_, Jul 12 2015
%E A257629 Corrected and extended by _Giovanni Resta_, Jul 14 2015
%E A257629 Corrected and extended by _Harvey P. Dale_, Jan 16 2017